Hideki Ohira

Title: Functional association of brain and body in affective decision making

Abstract: Though traditional microeconomics has supposed that human decisions are based on logical and exact computation of cost-benefit balances or efficacies, studies in behavioral economics and psychology have shown that humans sometimes make irrational decisions driven by affects, especially when values of options and contingencies between options and outcomes are uncertain. Some theorists argued that one important source of such affective drives influencing decision making is bodily responses which are represented in brain regions such as the insula and anterior cingulate cortex. In this talk, empirical evidence for the functional associations of the brain and body accompanying affective decision making will be shown as follows. (1) Heart rate responses and concentration of inflammatory cytokine (IL-6) can predict acceptance or rejection to an unfair offer in an economical negotiation game, the Ultimatum Game. Activation of the anterior insula mediates this phenomenon. (2) Enhancement of interoception by biofeedback technique affects decision making with risk. (3) Sympathetic responses reflected by secretion of epinephrine are represented in brain regions such as the midbrain, anterior cingulate cortex, and anterior insula, and furthermore can determine randomness of decision making in a situation where action-outcome contingency is stochastic and unstable.